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AssigneesKorea Atomic Energy Research Institute, Korea Electric Power Corporation
InventorsHeungseok Kang, Keenam Song, Kyungho Yoon, Hyungkyu Kim, Taehyun Chun, Dongseok Oh, Wangkee In, Yeonho Jung
Estimating the term…
A double strip mixing grid for nuclear reactor fuel assemblies is disclosed. This grid is fabricated by intersecting at right angles a plurality of double strips, each fabricated by welding two thin sheets together into a single structure with coolant channels. The mixing grid, having the channels, effectively mixes low temperature coolant with high temperature coolant within a fuel assembly, thus improving the thermal efficiency of the fuel assemblies. This mixing grid also effectively prevents the coolant from being partially overheated, thus improving the soundness of nuclear reactors. This mixing grid also has swirling flow blades and/or lateral flow blades to further improve the thermal efficiency of the fuel assembly. This mixing grid elastically supports the fuel rods by the sheets of the double strips, collaterally acting as positioning springs. Each double strip also has a vertical slot at a position around each channel, and so the elastic range of the positioning springs of the grid is preferably enlarged. The slots also enlarge the fuel rod contact area of the grid, thereby effectively protecting the fuel rod from fretting corrosion. In addition, the intersecting strips are welded together at the intersections through a continuous welding process, thus improving the mechanical strength of the grid.
A double strip mixing grid for nuclear reactor fuel assemblies, comprising a plurality of inner double strips, each fabricated by integrating two thin sheets together into a single structure having a plurality of coolant channels and intersecting each other at a predetermined angle to form a desired mixing grid having a plurality of four-walled cells, wherein each of said strips is partially cut away at predetermined portions from its top edge to form nozzles of said coolant channels, a plurality of mixing blades are provided at top portions of the strips for forcing coolant flowing inside the channels to be actively mixed with coolant flowing outside the channels, thus improving coolant mixing effect of the grid, and said two thin sheets are integrated in such a manner that each of said plurality of mixing blades provided at top portions of the strips faces one of said predetermined portions cut away from top edge to form nozzles for said coolant channels.
Dependencies are inferred from the claim text.